Security Challenges in the Black Sea: Military Exercise or a Navy Blockade? Analysis of the Russian Navy Activities in Bulgaria’s Exclusive Economic Zone in the Black Sea

[Dobrin Dobrev is a recent graduate from Utrecht University’s master’s program in International Law from the Conflict and Security track.]

1. Introduction

On the 24th of February 2022, the Russian Federation launched a full-scale invasion against Ukraine, marking the beginning of the biggest European conflict in the 21^st century. Since the invasion began, the Black Sea has received significant attention due to its military strategic importance. For instance, Ankara enforced Article 19 of the 1936 Montreux Convention closing the Bosporus to Russian warships. The blockade of the entrance towards the Russian military vessels strategically hinders Russia’s ability to reinforce its military. Any loss of Russian naval battleship due to Article 19 would be irreplaceable in their campaign against Ukraine.

2. The Occupation of Snake Island

At the beginning of the invasion, the Russian warships attacked Snake Island, held by Ukrainian forces. The attack was successful, leading to 13 Ukrainian casualties and occupation of the island. In April 2022 the Ukrainian forces began a counteroffensive from Odessa and launched two R-360 Neptun anti-ship missiles, which successfully destroyed the Russian battleship “Moskva”. This significantly reduced the Russian naval capabilities in the Black Sea. 

Recently, the Russian Federation has backed off from the grain deal, which allowed them to inspect ships for weapons in a 574 km corridor in the Black Sea. The Russian defense minister has declared that “any ship leaving a Ukrainian port will be a legitimate military target” Ukrain’s main grain ports are Odesa, Chornomorsk, Pivdennyi and Ismail. These ports have been subjected to continuous attacks in recent weeks, such as the more recent ones in Odessa and Ismail on the Black Sea. The probable aim of these strikes was to destroy Ukrainian ports, damage the grain, and devastate the Ukrainian economy.

In July 2023 the Russian navy a began military exercise (red square on the map), in Bulgaria’s exclusive economic zone. 

3. Russian Military Exercises and Bulgaria’s Response 

In August and September 2023, Russia further extended its military exercises in the Black Sea. Bulgaria’s defense minister, Todor Tagarev, called this actions an obvious provocation and partial blockade. In response, Bulgaria announced a €20 million deal with the SAAB to urgently acquire RBS-15 missiles for its Coast Guard.  

In response to the instability towards the security in the Black Sea region, Tagarev has also announced that soon an operation with the aim of mine search and clearing will begin in collaboration with its NATO allies Romania and Türkiye.

4. Russian Blockade in Bulgaria’s Economic Zone?

In the 1990s, many scholars believed that the operational practice of blockades was almost extinct. Contrary to scholars’ previous beliefs, the present situation in the Black Sea demonstrates that the laws of blockades are still relevant. The term “blockade” is not explicitly defined in international treaties, leaving the topic as a subject of interpretation and more precisely under customary international law (for e.g. Hague Convention No.XII of 1907 and Art.3(c) of the A/RES/3314). A blockade can be defined as 

“an operation by a belligerent State to prevent vessels and/or aircraft of all States, enemy as well as neutral, from entering or exiting specified ports, airfields, or coastal areas belonging to, occupied by, or under the control of an enemy belligerent State”.

As Frostad notes, a navy blockade may only cover a portion of a state’s coastline. Furthermore, current blockades are a crucial component of military operations targeting military resources. It is also important to note that the blockade “avoids the need to distinguish between the cargoes carried by neutral ships, and so overrides of contraband” and is the only military tactic used in conventional naval warfare that allows for the disruption of enemy exports.

In the area of international law of the sea, a blockade must comply with a number of specific conditions. First, the blockade has to be notified with all aspects including the location, and duration, and it must be effective. In an interview Tagarev it became apparent that the Russian Federation has announced that it would begin ‘military navy exercises’ in the middle of June 2023 which mostly will take place in the exclusive economic zone of Bulgaria. Here the technical formality does not decide the legal classification of the Russian navy’s announcement. In support of this argument, the San Remo Manual claims that the naval blockade regulations “were applicable to blockading actions taken by States regardless of the name given to such actions.” 

Regarding the effectiveness of the blockade, the Russian Federation closed most of Bulgaria’s exclusive economic area until the end of September 2023. This Russian naval exercise in the exclusive economic zone of Bulgaria seems to satisfy the fundamental criteria of a naval blockade, including declaration, notification, impartiality, and effectiveness. This would mean that despite being proclaimed a “military exercise” it is a de facto effective partial blockade in the Black Sea. 

5. Dangers to Merchant Ships Passing by the blockade 

5.1. Merchant Ships as Legitimate Targets?

Targeting neutral ships under international humanitarian law (hereinafter ‘IHL’) outside of territorial waters is permitted under certain case scenarios. Firstly, is in accordance with Article 52 of Additional Protocol I of the Geneva Conventions and Paragraph 40 of the San Remo Manual attacks should be limited to military objectives and should be against objects that “by their nature location, purpose or use make an effective contribution to military action and whose total or partial destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage.”( Geneva Conventions Additional Protocol 1, Art. 52 and San Remo Manual Paragraph 40). In such a situation, unless a merchant ship satisfies one of the requirements from the above-mentioned text, the ship will not be a legitimate military target for the Russian navy.

Secondly, legitimate military targets for the Russian navy in the area of the blockade could be those such as the ones that satisfy one of the different criteria under Paragraph 67 of the San Remo Manual such as if the merchant ship acts on behalf of the enemy, or the ship is “believed on reasonable grounds to be carrying contraband.” Another exception would be if the Russian navy has “given a warning shot and the merchant ship is intentionally and clearly refusing to stop” or the ship or ships “are incorporated into or assist the enemy’s intelligence system.” However, although the San Remo Manual is not a binding document as the Geneva Conventions, the manual is viewed by scholars such as Enny Narwati as codifying existing customary international law and integrating the existing legal standards for naval warfare. The argument is based on the fact that the San Remo Manual 1994 itself is an amendment to the existing provisions of the Hague Convention 1907, The Geneva Convention 1949, and Additional Protocol I 1977. On this basis, the regulation outlined in the San Remo Manual of 1944, originates from international treaties that also hold a position as customary international law. The present San Remo Manual of 1994 has been made by 56 experts, containing fundamental legal principles and is progressing towards becoming customary international law.

In conclusion, it is reasonable to presume that the circumstances outlined in Paragraph 67 in the San Remo Manual or satisfaction of the Art. 52 of AP1 will give the Russian Navy legitimacy to use force against neutral commerce ships outside of their territorial waters, in particular in the present situation the zone of blockade that is mostly in the exclusive economic zone of Bulgaria. 

5.2. Visit and Search on the Merchant Ships by the Russian Navy 

As mentioned previously the Russian Federation has withdrawn from the grain deal which permitted Ukraine to transport its grain across the Black Sea. Near the blockade, a Turkish cargo ship called “Sukru Okan” was on its routine journey to pick up grain from the Danube ports to European and Turkish docks. However, a Russian warship fired warning shots to forcefully stop the vessel for an inspection. The aftermath of the situation was that a Russian Ka-29 helicopter boarded the cargo ship with servicemen that captured the Sukru Okan crew and began interrogating them.

The right in international waters of “visit and search” refers to the authority of warships from belligerent nations to inspect foreign merchant vessels to verify that they are not transporting prohibited goods to the enemy. This right is understood to be a reflection of customary international law practice.

The San Remo Manual addresses this procedure by stating that “neutral vessels” may undergo inspection and search beyond “neutral territories” when there are valid suspicion grounds of their susceptibility to capture. Paragraph 146 of the San Remo Manual discusses when ships fall under the category of being ‘subject to capture’ and relates back to paragraph 67, indicating that a ship which can be singled out for targeting is also eligible for capture. In particular, paragraph 146 introduces further scenarios under which neutral ships can contribute to the enemy’s war efforts such as carrying contraband, operating under enemy control, breaching or attempting to breach a blockade, violating a regulation established by a belligerent and other scenarios.

It is important to note that the right to ‘visit and search’ a vessel is not only included in the San Remo Manual but also can be found in the Helsinki Principles. According to paragraph 5.2.1, it is explicitly stated that “belligerent warships have a right to visit and search vis-à-vis neutral commercial in order to ascertain the character of their cargo.” A similar wording approach can be found also in Article 1 of the Havana Convention which gives the right to warships from belligerent nations to intercept and inspect merchant ships on the high seas and in non-neutral territorial waters. 

It becomes evident that IHL acknowledges the “visit and search” rights of vessels but the scope remains uncertain. The San Remo Manual stands as the primary reference on the subject, stipulating the right is contingent upon suspicions regarding a particular ship’s connection to an enemy entity. The present incident presented with the Turkish cargo ship “Sukru Okan” serves as a real-world example of the complexities surrounding the exercise of this right, and highlights the need for greater clarity and understanding within the realm of maritime law.

6. Conclusion

The Black Sea situation raises stakes and risks in the region. The naval blockade, which was considered nearly extinct, has been resurrected as a crucial element in Russia’s strategy against Ukraine. The exercise of the “visit and search” right by Russia further complicates the situation, posing a threat for NATO members in the region like Bulgaria, Romania and Türkiye. 

According to Article 57 of the United Nations Convention of the Law of the Sea (UNCLOS), merchant ships passing through the exclusive economic zones shall not extend beyond 200 nautical miles, or otherwise will find themselves in a dangerous position. This is because as Helmersen notes that “if a state uses force against a neutral merchant ship in another state’s exclusive economic zone(EEZ), this does not constitute a use of force against the coastal state, but only against the ship’s flag state.” However, an armed attack against a vessel in a foreign state’s territorial waters which according to article 3 of UNCLOS extends to 12 nautical miles will constitute an armed attack towards that country irrespective of the ship’s flag.

Merchant ships should avoid the EEZ of Bulgaria and pass by the territorial waters of the country, as the ships will be not only protected by the state, itself but in case of an armed attack of a vessel, Bulgaria could invoke Article 5 as a NATO member state. Despite the increased shipping distance, merchant ships’ security in the Black Sea will be better guaranteed if they pass by the territorial waters of Romania and Bulgaria to Turkey avoiding the EEZ zones. Bulgaria cannot currently use its EEZ zone effectively and high defense investment is necessary in its navy and coastal defense in case of an unwanted scenario in the EEZ for the country to be able to respond with long-range coastal defense missiles such as the ones that the country recently purchased RBS-15 Mk3 which have a range of 200 km. A potential purchase of Mk4 should be also a consideration.